The Guam Environmental Protection Agency has fined Andersen Air Force Base for sanitizing some of its drinking water with chlorination tablets made for sanitizing swimming pools, a 36th Wing spokesman said in a statement Saturday.

The Guam EPA issued a notice of violation Jan. 2 that the brand of chlorination tabs the base was using on drinking water included a chemical compound the agency considers a pesticide, according to the notice. The compound is toxic to waterborne organisms such as water fleas, according to the EPA Office of Pesticide Programs.

“Trichloro-s-triazinetrione is used only for swimming pools as per the product labeling,” Guam EPA wrote in the notice.

The issue came to light during a routine inspection Dec. 28 when two Guam EPA agents noticed the base was using a commercial pool sanitizer called “Pool Time Chlorination Tabs” instead of its approved MIOX disinfection system, which had gone out of service, according to the agency. MIOX is a brand name for mixed oxidant solution.

The water tank operator told the inspectors that he did not know how long the base had been using the pool tablets in drinking water, according to the Guam EPA.

Guam EPA fined the base $750 for violating the Guam Pesticide Act and $1,700 for violating the Guam Safe Drinking Water Act, according to the notice.

People who may have been exposed to the affected drinking water were sent a public notice of the finding on Jan. 15, according to the statement.

Guam EPA and Andersen Air Force Base both found it was “very unlikely that the use of the Pool Time chlorination tabs resulted in any adverse health effects,” Bumpus said in the statement.

“Although Andersen Air Force Base received the notices of violation for the Northwest Field water tank, at no time was the water deemed unsafe to drink,” Bumpus said in the statement.

Chlorine has been used as a water disinfectant in the United States since 1908, according to U.S. Centers for Disease Control’s official website. By 1990, 64% of American community water systems used chlorine to disinfect water.

“Current studies indicate that using or drinking water with small amounts of chlorine does not cause harmful health effects and provides protection against waterborne disease outbreaks,” the CDC said on its website.

However, trichloro-s-triazinetrione has “the highest available chlorine content of [all] solid chlorine sanitizers,” therefore it is more traditionally used in swimming pools, according to a handout by the Association of Pool and Spa Professionals.

The base’s northwest field water tank only provides water to the northwest field, according to the statement. Other areas of Andersen Air Force Base were unaffected.